Expression of type Lambda

from the theory of proveit.physics.quantum.circuits

import proveit
# Automation is not needed when building an expression:
proveit.defaults.automation = False # This will speed things up.
proveit.defaults.inline_pngs = False # Makes files smaller.
%load_expr # Load the stored expression as 'stored_expr'
# import Expression classes needed to build the expression
from proveit import Lambda, n
from proveit.physics.quantum.circuits import register_meas

# build up the expression from sub-expressions
expr = Lambda(n, register_meas)

expr:

# check that the built expression is the same as the stored expression
assert expr == stored_expr
assert expr._style_id == stored_expr._style_id
print("Passed sanity check: expr matches stored_expr")

Passed sanity check: expr matches stored_expr

# Show the LaTeX representation of the expression for convenience if you need it.
print(stored_expr.latex())

n \mapsto \left(\begin{array}{c} \Qcircuit@C=1em @R=.7em{
\multiqin{3}{\lvert \psi \rangle} & \meter & \multiqout{3}{\lvert n \rangle_{m}} \\
\ghostqin{\lvert \psi \rangle} & \meter & \ghostqout{\lvert n \rangle_{m}} \\
\ghostqin{\lvert \psi \rangle} & \measure{\begin{array}{c}:\\ \left(m - 3\right) \times \\:\end{array}} \qw & \ghostqout{\lvert n \rangle_{m}} \\
\ghostqin{\lvert \psi \rangle} & \meter & \ghostqout{\lvert n \rangle_{m}}
} \end{array}\right)

stored_expr.style_options()

no style options

# display the expression information
stored_expr.expr_info()

	core type	sub-expressions	expression
0	Lambda	parameter: 39 body: 2
1	ExprTuple	39
2	Operation	operator: 3 operands: 4
3	Literal
4	ExprTuple	5, 6, 7
5	ExprTuple	8
6	ExprTuple	9
7	ExprTuple	10
8	ExprRange	lambda_map: 11 start_index: 36 end_index: 40
9	ExprRange	lambda_map: 12 start_index: 36 end_index: 40
10	ExprRange	lambda_map: 13 start_index: 36 end_index: 40
11	Lambda	parameter: 35 body: 14
12	Lambda	parameter: 35 body: 15
13	Lambda	parameter: 35 body: 17
14	Operation	operator: 21 operands: 18
15	Operation	operator: 19 operands: 20
16	ExprTuple	35
17	Operation	operator: 21 operands: 22
18	NamedExprs	element: 23 targets: 26
19	Literal
20	NamedExprs	basis: 24
21	Literal
22	NamedExprs	element: 25 targets: 26
23	Operation	operator: 27 operands: 28
24	Literal
25	Operation	operator: 29 operands: 30
26	Operation	operator: 31 operands: 32
27	Literal
28	NamedExprs	state: 33 part: 35
29	Literal
30	NamedExprs	state: 34 part: 35
31	Literal
32	ExprTuple	36, 40
33	Variable
34	Operation	operator: 37 operands: 38
35	Variable
36	Literal
37	Literal
38	ExprTuple	39, 40
39	Variable
40	Variable